Dimpling Monitoring and Assessment of Satellite Honeycomb Sandwich Structures by Distributed Fiber Optic Sensors

Dimpling in the face sheets of honeycomb sandwich structures due to mismatch in the thermal expansion coefficient of the constituent materials, with emphasis on its monitoring and assessment, was studied by utilizing embedded distributed fiber optic sensors. Strain distributions along optical fibers embedded in the face sheet of the sandwich structures were monitored during manufacturing. Based on finite element analysis results, the strain data was interpreted and dimpling monitoring capability was discussed. Simple analytical model to predict the dimple profile and thus assess the dimpling condition from the strain data was also presented and evaluated.